If the window frames in your home are in rough shape, they will have to be removed and replaced. Because of that, full-frame replacements are the best choice. Some homes will require full-frame windows to be installed if the existing window does not have a frame, which is often seen in older homes.
During the installation of a full-frame window replacement, the entire unit is removed, exposing a rough opening of framing studs like in a new home construction. Everything is removed, including the sashes, framing, and trim. A new unit is then installed with new insulation and trim. A full-frame installation is recommended when there is significant deterioration or rot to the exterior wood components of a window opening. In some instances, this option is the best to prevent the resulting glass loss that inserts create. In others, the full-frame option allows direct access to wall voids or gaps around the old frame, so insulation can be installed and to create a barrier to prevent air or water from getting in.